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Transcript of Polymers containing p-block elementsgbdong.cm.utexas.edu/seminar/2015/2015-11-04.pdf · Polymers...
Polymers containing p-block elements
Guangbin Dong Group Literature MeetingNov. 4th, 2015Ki-Young Yoon
Polymer Era
Sudden ubiquity of polymeric materials since 20th century
Relative Importance of the four classes of materials (Metal, Polymer, Composites, Ceramics)
Organic (C,N,O) polymers
Carbon-based polymer backbone(C, N, O)
Limited to incorporate various functions into polymeric materials
Polyester, Polyamide
Metallopolymers
I. Manners, Nat. Mater. 2011, 10, 176.
Polymer backbone containing metals (esp. transition metal)
P-block Polymers
I. Manners, ACIE 1996, 35, 1602.
polysiloxane polyphosphazene polysilane poly(ferrocenylsilane)
General Challenges
D. P. Gates, Chem. Soc. Rev. 2015, ASAP.
Conventional synthetic protocols to organic polymersare difficult to use for inorganic polymer synthesis
General Challenges
D. P. Gates, Chem. Soc. Rev. 2015, ASAP.
Reactive but stable multiple bonds involving inorganic elements
Key issue
Suitably strained inorganic ring compounds
Highly pure monomer/stoichiometric imbalance
General Challenges
D. P. Gates, Chem. Soc. Rev. 2015, ASAP.
Reactive but stable multiple bonds involving inorganic elements
Key issue
Suitably strained inorganic ring compounds
Highly pure monomer/stoichiometric imbalance
Organic spacer-> conventional organic reaction
Group 13 : Boron
Poly(borazylene)s Precursors to Boron-Nitride ceramic ([BN]n)
Stable and volatile Me3SiCl
High yield
Oligomer or highly cross-linked polymer(poor solubility, hard to characterize)
Increase solubility
Chem. Rev. 1990, 90, 73
Group 13 : Boron
Poly(cycloborazane)s
THF, r. t.
Mn=4800-9400PDI=1.5-1.6
Mn=1800-4200PDI=1.4-2.8
Yellow fluorescence in both solution and solid state
J. Organomet. Chem. 2003, 680, 27
Group 13 : Boron
Polymer containing organboron heterocycles (B-quinolate)
B-quinolate 4a : Mn=3200 PDI=1.74b : Mn=8800 PDI=2.4
Green-blue fluorescence material Low quantum yield
Various quinolates(benzoquinolates, aminoquinolates, quinolone thiolates, etc.)
Macromolecules 2007, 40, 6
Group 13 : Boron
Polymer containing organboron heterocycles (B-quinolate)
4a : Mn=3200 PDI=1.74b : Mn=8800 PDI=2.4
Green-blue fluorescence material Low quantum yield
Various quinolates(benzoquinolates, aminoquinolates, quinolone thiolates, etc.)
Macromolecules 2007, 40, 6
Macromolecules 2009, 42, 3448
Mn=14300 PDI=1.2
Thermally stable (<300 oC)Soluble
Angew. Chem., Int. Ed., 2009, 48, 2313
Post-functionalization
Group 13 : Boron
Polymer containing organboron heterocycles (BODIPY)
F F
Various AB-alternating copolymer (-ABABABABABAB-) by Sonogashira, Suzuki, Stille coupling polymerization
Etc…
D. P. Gates, Chem. Soc. Rev. 2015, ASAP.
RSC Adv., 2013, 3, 10221
BODIPY homopolymerMn=2630, PDI=1.59
Highly emissivemolecule
Various AB-alternating copolymer (-ABABABABABAB-) by Sonogashira, Suzuki, Stille coupling polymerization
pyrazabole
Group 13 : Boron
Polymer containing organboron heterocycles (Azaborine)
NH-pi interaction
Angew. Chem., Int. Ed., 2015, 54, 11191
Group 13 : Boron
Dehydrocoupling polymerization (Amine-Borane)
Polyethylene/polypropyleneAnalogue
Boron-Nitride ceramic precusor
Aminoboranes : potential hydrogen storage materials
Angew. Chem., Int. Ed., 2008, 47, 6212
Mn=55200, PDI=2.9
After pyrolysis at 900 oC
Group 13 : Boron
Poly(arylene/vinylene/ethynylene boranes)
Low MW bulky substituents needed for air/moisture stability
Group 13 : Boron
Borole-containing polymers
Mn=22900, PDI=1.78
Promising ion sensor
F-, CN-
Br-, Cl-,
Luminescence quenching
No effect
J. Polym. Sci., Part A: Polym. Chem., 2008, 46, 2878
Group 13 : Gallium
Heavier group 13 elements : inherent moisture/air instability
Weak, but still conjugation exists
Chem. Commun., 2014, 50, 15740
Group 13 : Gallium
Ring opening polymerization of Gallaferrocenophane
Mw=36000
J. Am. Chem. Soc., 2010, 132, 1794
Group 14 : Silicon
850 kTon/year
Polysiloxanes Chain-growth
Step-growth
Post-functionalizing byHydrosilylation
example
Group 14 : Silicon
Polysiloxanes by metal-catalyzed reaction
Syndiotactic polymer
Acid/base-sensitive polymer
dehydrocoupling
hydrosilylation
Group 14 : Silicon
Polysilanes
Wurtz Coupling : incompatible with functional substituentspolymodal MW distribution
Electrolysis : Low/medium MWM-cat : Low/medium MW
Wurtz coupling
Group 14 : Silicon
Polysilanes (Ring opening polymerization)
Making suitable cyclic monomers is challenging
Macromolecules, 1994, 27, 2360
Group 14 : Silicon
Polysilanes (Ring opening polymerization)
Both substituents couldn’t tolerate under Wortz coupling
Masked disilene
J. Am. Chem. Soc., 1989, 111, 7641
Angew. Chem., Int. Ed., 1998, 37, 1441
Mn=53000 PDI=1.5
All about substituent variation
Group 14 : Silicon
Secondary structure
Influence of the substituents
J. Organomet. Chem., 2014, 772–773, 143
Chiral ligand
Group 14 : Silicon
Polycarbosilanes (Ring opening polymerization)
Macromolecules, 1999, 32, 6003
Controlled/living polymerization
J. Polym. Sci., Part A: Polym. Chem., 1997, 35, 3207